Cher swept her costars away during the making of Mamma Mia! Here We Go Again.
The 72-year-old icon, who has Armenian roots, plays Ruby, the mother of Meryl Streep‘s character in the film, who comes to visit the little Greek island her granddaughter, Sophie (Amanda Seyfried), calls home in the 2018 hit sequel.
In a PEOPLE exclusive clip, Cher’s costars couldn’t help but gush about the singer’s performance of ABBA’s “Fernando” during the film.
“The anticipation that we were going to meet Cher made the air crackle,” Colin Firth says. “I actually wonder what it felt like for her because we were all rather awestruck.”
Dominic Cooper, who plays Seyfried’s love interest in the film, agrees.
“She walked up onto the stage and then that voice comes out,” he marvels.
ABBA singer and film producer Björn Ulvaeus was amazed at how well she sang their hit 1980 song.
“To hear her sing ‘Fernando’ was a perfect revelation. She was perfect for that song,” he says, smiling.
The film’s producer, Judy Craymer, adds, “Cher literally does own that song. The atmosphere on set was like everyone was just in a glow of happiness and warmth.”
“The lyrics just totally grabbed me. It was so heartfelt and tender,” Cher says of “Fernando,” he climactic number in the film. “When I used to hear ABBA it was amazing. They know how to write a story.”
“It was like a performance and this was very much an acting performance first,” she adds.
Lily James, who plays Cher’s daughter, couldn’t help but share her love of the singer, saying, “She’s such a rockstar!”
The film is available on digital on Oct. 9 and in Blu-Ray and DVD on Oct. 23.